A Level Physics Practice Exam

What is the fundamental frequency in terms of harmonic vibrations?

1. The frequency of the second harmonic

2. The frequency of the first harmonic

3. The frequency of the third harmonic

4. The average frequency of all harmonics

The correct answer is: The frequency of the first harmonic

The fundamental frequency is recognized as the lowest frequency produced by a vibrating object, serving as the first harmonic in a system of harmonic vibrations. When a system vibrates, it does so at multiple frequencies, which are known as harmonics. The first harmonic corresponds directly to the fundamental frequency and represents the simplest mode of vibration where the entire length of the vibrating medium moves in a single complete wave cycle. This is often visualized as a sine wave in cases like a string fixed at both ends. In contrast, the second harmonic is twice the frequency of the fundamental, and the third harmonic is three times that frequency. The average frequency of all harmonics does not have a precise definition in the same context, as harmonics vary significantly based on the properties of the vibrating medium and the specific type of wave being produced. Hence, the fundamental frequency is distinctly identified as the frequency of the first harmonic. Understanding this is crucial in wave physics and helps in recognizing how different frequencies interact and contribute to sound and other wave phenomena.